Gauge not working on XP


I use Microsoft Visual C++ 2010 to create my gauges. I use Windows 7 for years and everything is fine.
A friend of mine tried to use one of my gauges with FS2004 and Windows XP. Bad surprise, it didn't work. fs9 says it cannot load the gauge (in the aircraft selection screen).

I have an old machine with XP, I tested and got the same result: it didn't load. A long time ago, when I had Windows XP, all my gauges were created using Visual C++ 2003. With VC 2010, it seems my generated gauges cannot work with XP any more. I look into all the compilation and linker options but couldn't find why it doesn't work, there is nothing specific to Windows 7 or 64-bit system (the target is still X86, which should work for 32-bit and 64-bit OS).

Please let me know if you have any idea.

My gauges usually use very few Windows API calls. This gauge uses FSUIPC but again, the use of FSUIPC library does not cause a use of specific Windows API calls.
Nevertheless, I will check my code for this, who knows...

Thanks for the tip :)
There was a call to SetWindowsHookEx. According to Microsoft documentation, this may cause a compatibility problem. I removed this call (it was useless anyway) but it didn't solve the problem.
I also removed most of the libs in the linking options, but the problem is still there...
Check that they have the Visual Studio Runtime distributables installed. Fairly confident that if it's not your code causing the problem, it would be that.